Localization of neuroregulators, substances which may be transmitters or modulators in neuronal and hormonal structures using the electron microscope. Particular attention would be directed to opioid peptides. Structures examined would include brain and such endocrine organs as the pituitary gland. Through morphological examination and studies of biochemical neuroanatomy it should be possible to learn more about the functional relationships of various neuroregulators. This request for equipment is a supplement to an on-going program-project grant, MH 23861.